Incandescent lamp.



U. U..WOODWORTH.

INGANDESGENT LAMP.

APPLIOATION FILED JULY 1, 1908.

925,790, Patented June 22, 1909.

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PATENT OFFICE.

CHARLES o. WOODWORTH, or roa'fLAND, OREGON, I

. 1' INCANDESCENT LAMP.

Specification of Letters Patent.

Patented June 22, 1909.

Application filed m 1, 1908. Serial No. 441,286.

To all whom it may concern: Be it known that I, CHARLES C. W001)- WORTH, a citizen of the United States, "and a resident of Portland, in the county of Mult- 5 nomah and State of Oregon, have invented a new and useful Improvement in Incandes-. cent Lamps, of which the following is a specification.

My invention relates to incandescent, lamps adapted to be connectedin series with a high potential circuit.

' The object of my invention-is to provide an incandescent lamp which may be con nected in Series with a high potential distribution system and which is so-constructed and arranged that, in case of a burn-out, the line will not be opened and the other lamps will remain at or near their normal voltage. With this object in view myv invention consists of an incandescent-lampwhichmay be of the ordinary type provided with an automatic cut-out in its base and so constructed as to connect a compensating resistance in series with the power circuit and in shunt with. the lamp filament when the latter for any reason is ruptured as in case of a burn-out. Y My invention also consists in magnetically operated means for'so connecting the said compensating resistance in series with the power circuit and in shunt with the filament and at the same time short-circuiting saidmagnetihally operated means so that all the power circuit current passes through the compensating resistance. 7

My invention further consists in means for locking in predetermined position the moving parts of said automatic cut-out and n magnetically operated means for releas- 40 mg said moving parts and placing them in their original position.

In the drawing which accompanies and forms a part of this specification, the figure represents an incandescent lamp partly in section constructed in accordance with the present invention.

In the figure, A'represents an incandescent lamp of the ordinary type, for example, an Edison lamp provided with a filament 50 C and secured in the usual manner to the metallic base 13.. The base of the usual ineandescent lamp is filled with 1 plaster of arisor other material in which the leads ii'om the filaments to the lamp terminals are embedded. I have found that the space occupied by said material in the base of the lamp is ample to carry the automatic cut-out and resistance hereinafter described, but it will be understood that I do not limit myself to a lamp ofthe ordinary type carryingsuch devices in its base, except as specified in r the appended claims,

In the specific example which I haveillustrated for the purpose of more fully disclosmg my invention, D represents an electromagnet connected in series with the lamp terminals a b and in shunt with the filament C, the points 0 dindicating the juncture of the terminals of the filament with the terminals of said magnet D.- The magnet D is wound, to have the resistance higher than that of the filament, so, that during the normal operation 01 the lamp, the said magnet is not sufiiciently energized to attract its armature F which is normally held against 75 its back-stop H by the spring G. E represents afnelectromagnet connected in series with the lamp terminals a b and in series with the filament C. V L is a compensating resistance which-preferably is equal to the resistance of the lamp filament, and as shown, said resistance has one terminal connected to "the armature F of the magnet D and the other terminal connected to the terminal a of the lamp.

K represents a conductor ofany suitable shape provided with a notch or other retaining device adapted to hold the armature J which is connected by the spring I to the armature F and which is insulated from the latter as shown. The lower end of the member K serves as a front-stop H to the armature F.

. It will be understood of course that the several elements above described are secured in any suitable manner to the base of the lamp and that theymay be insulated therefrom in any of the usual ways necessary.

The operation is as follows: When there is a circuit through the filaments, the current passes fromthe lamp terminal a through the filament and then through the magnet E to d K H and finally to the lamp terminal-b. Inasmuch as the armature J of the magnet E is outside the field of force of the latter duringthe normal operation of the lamp, it follows that said armature. is normally inactive. Should \the circuit through the filament be opened as by disruption due toburn-out or other cause, the magnet D will carry all the current of the power circuit and will attract its armature F to its front-stop H, said armature being retained in its attracted position by the armature J which is sprung into the notch K, thereby connecting across the terminals 0 d of said magnet the compensating IQSt ance L, so that the line current now passes through said resistance by the path a c e L F H b and thecontinuity of the power circuit as well as the normal voltage of the remaining lamps is maintained. When a burn-out has been discovered, the lamp is replaced by a new lamp and may be opened and have its filament renewed. When such A the filament.

renewed lamp is connected in circuit, a certain amount of current flows through the filament and its serially connected magnet E by the path a c C E d 11 hand energizes said magnet E, thereby causing the attraction of the armature J and the release of the armature F to its normal position; thereby cutting the resistance L out of the power circuit'and sending the entire current through T'do not wish to be understood as limiting myself to the apparatus and arrangement of circuits above described, inasmuch as it will be apparent thatmany modifications may be made in both the apparatus and circuit arrangements without departing "from the principle of my invention.

I claim:

1. The combination with an incandescent lamp of a resistance mounted in the base thereof, an electromagnet connected in'shunt with the lamp filament, a connection from the armature of said magnet to said resistlamp terminals and in shunt with the filament, an armature cooperating with said magnet and arranged to connect. said reslstance in series with the lamp terminals and in shunt with said magnet and filament,

means for locking said armature in its attracted position and means for releasing said armature.

3. The combination with an incandescent lamp of a resistance mounted in the base thereof, an electromagnet in series with the lamp terminals and in shunt with the filament, anarmature cooperating with said magnet and arranged to connect said resistance in series with the lamp terminals and in shunt with said magnet and filament, means for locking said armature in its attracted position and magnetically operated means forreleasing sai'd armature. 4E. The combination with an incandescent lampof a resistance substantially equal to the resistance of the lamp filament mounted in the base of the lamp, a n 'electromagnet of higher resistance than the said filament connected in series with the lamp terminals and 1n shunt with said filament, an electromagnet connected-in series with said terminals and in series with said filament, a connection from one of said lamp terminals to one terminal of said resistance, a connection from the other ,terminalof said resistance to the armature of the first mentioned magnet, a connection from the front-stop of said armature to the other of the said lamp terminals, :1 spring armature connected to but insulated from the first mentioned armature, and meansfor securing said spring armature in predetermined position'within the field of force of the last mentioned magnet.

In testimony whereof, I have hereunto subscribed my name this 8th day of June,

CHARLES C. WOODWORTH. Witnesses:

O. S. BRYANT, F. C. WRITTEN. 

